OFFSET
0,3
FORMULA
D-finite with recurrence a(n) -n*a(n-1) -9*a(n-2) +9*(n-2)*a(n-3)=0. - R. J. Mathar, Sep 29 2020
MAPLE
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Dec 18 2017
STATUS
approved